Field of the invention
[0001] The invention relates to a unit for preparing infusions comprising a capsule comprising
a cup-shaped main body defining a main axis and having an upper base and an open lower
base, a lid for closing said lower base and forming an inner chamber with said main
body in which there is contained an infusion product, a perimetrical rim projecting
outwardly from said lower base and having an injection side and an extraction side,
and a sealing member, provided on said injection side of said rim, and a device for
preparing infusions comprising an enclosing member configured to receive said capsule
and having a leading sealing edge, said device being configured to prepare an infusion
by causing a liquid to pass under pressure through said inner chamber, said unit having
a rest position in which said leading edge is remote from said sealing member and
an operative position in which said leading sealing edge is compressed against said
sealing member to provide fluid tightness during the preparation of said infusion.
[0002] The invention likewise relates to a capsule for use in a device for preparing infusions
comprising a truncated-cone-shaped enclosing member configured to receive said capsule
and having a circular leading sealing edge, said device being configured to prepare
an infusion by causing a liquid to pass under pressure through said inner chamber
and said leading edge having an inner diameter comprised between 29.8 and 30.4 mm
and an outer diameter comprised between 30.6 and 32 mm, said capsule comprising a
truncated cone cup-shaped main body defining a main axis and having an upper base
and an open lower base, a lid for closing said lower base and forming an inner chamber
with said main body in which there is contained an infusion product, a perimetrical
rim extending outwardly from said lower base and having an injection side and an extraction
side, and a sealing member, provided on said injection side of said rim.
[0003] Finally, the invention also to a method for preparing infusions comprising the steps
of: inserting a capsule comprising a cup-shaped main body defining a main axis and
having an upper base and an open lower base, a lid for closing said lower base and
forming an inner chamber with said main body in which there is contained an infusion
product, a perimetrical rim projecting outwardly from said lower base and having an
injection side and an extraction side, and a sealing member, provided on said injection
side of said rim, in a device for preparing infusions comprising an enclosing member
configured to receive said capsule and having a leading sealing edge, said device
being configured to prepare an infusion by causing a liquid to pass under pressure
through said inner chamber, said unit having a rest position in which said leading
edge is remote from said sealing member and an operative position in which said leading
sealing edge is compressed against said sealing member to provide fluid tightness
during the preparation of said infusion.
State of the art
[0004] The preparation of infusions of the type of tea, coffee or the like from units for
preparing infusions formed by a device injecting a fluid, preferably hot water, under
a pressure of between 1 and 20 bar in a capsule containing one or multiple doses of
the infusion to be prepared, of the type described at the beginning is known.
[0005] One of the problems that this way of preparing infusions presents consists of it
being complicated to achieve correct fluid tightness at the contact point between
the enclosing member of the capsule holder of the machine and the rim of the capsule
itself. The enclosing member bears with its leading edge on the sealing member of
the capsule provided on the rim. Unless good fluid tightness is achieved at this bearing
point, and fluid losses and a drop in the pressure of the fluid injected in the capsule
occur. Consequently, the organoleptic properties of the beverage are directly affected.
[0007] In particular,
EP2303077A1 discloses a solution in which to achieve the fluid tightness at the contact point
between the enclosing member and the rim on which the capsule holder bears, the capsule
is provided with a sealing member formed by a plurality of very closely spaced apart
concentric annular lips. Thus, the leading edge of the enclosing member bears on the
peaks of these lips to guarantee the fluid tightness of the system during the injection
of the fluid. Such sealing member having the plurality of lips is directed to minimizing
liquid losses should the enclosing member and the capsule be mutually offset. Nevertheless,
particularly when the offset has occurred, the loss of a certain amount of liquid
is not avoided. Thus, this solution only minimizes the problem.
[0008] WO2014184652A1 discloses a sealing member formed through a lip forming a trough in the capsule rim.
Under this trough, on the extraction side of the capsule, the rim is provided with
a step. When the capsule holder presses against the trough, owing to the step under
the sealing member, the lip is deformed inwardly to block the outer surface of the
enclosing member. In this case, there is also the risk of the capsule holder itself
bearing on the trough in an offset way, such that not all the lip bears against the
outer profile of the enclosing member. Also, when the offset is very great, the enclosing
member can press the lip and then the desired effect of fluid tightness is not attained.
[0009] Finally,
WO2014118812A1 discloses a capsule having a sealing member formed by two concentric lips remote
from the main body of the capsule. The same as in the case of
WO2014184652, there is provided on the extraction side of the capsule rim a step to facilitate
the bearing of both ribs against the side walls of the enclosing member when the latter
presses against the floor of the trough formed between both ribs. Once again in this
case, the problem arises that the enclosing member might not correctly enter in the
trough, reproducing the already described problems.
Summary of the invention
[0010] It is an object of the invention to provide a unit for preparing infusions of the
type indicated at the beginning, guaranteeing a good fluid tightness in the point
of closure of the enclosing member on the capsule and that this fluid tightness may
be effected in a simple, but reliable, way.
[0011] This purpose is achieved by a unit for preparing infusions of the type indicated
at the beginning, characterized in that said sealing member comprises an annular groove
surrounding the main body and which is formed by the side wall of said main body and
a remote wall from said main body, said groove narrowing from the injection side towards
the extraction side, and in that said groove and said leading edge are configured
in such a way that, in the operative position, said leading edge is inserted in said
groove and is sealingly compressed simultaneously on said side wall of said main body
and said remote wall.
[0012] In the first place, it is important to highlight that it is not essential in the
invention whether the enclosing member moves in the longitudinal direction or rocks
relative to the capsule, but it may also be the other way round. Thus, in the invention,
to pass from the rest position to the operative position, it is irrelevant which of
these two members moves towards the other.
[0013] The narrowing of the annular groove and the shape of the leading edge of the enclosing
member are configured and orientated in such a way that, in the operative position,
the leading edge of the enclosing member contacts and then compresses the walls delimiting
the groove. Thereby, firstly, thanks to one of the walls of the groove being the side
wall proper of the capsule, direct guidance is achieved between the leading edge of
the enclosing member and the capsule leading the enclosing member always ending to
be inserted in the annular groove of the sealing member. This guarantees that the
capsule is centered in the enclosing member such that the leading edge of the enclosing
member has available two sealing curves on the sealing member. This notably improves
the fluid tightness at this point.
[0014] Also, unlike other conventional solutions in which guidance is effected through the
end of the capsule opposite to the end having the rim, in the invention, the guidance
is effected precisely at the leading edge, that is, precisely at the point where it
seeks to enter the groove to improve the fluid tightness. Consequently, the assembling
between both members is more precise than in the known conventional solutions, in
which the guidance is effected from the smaller base of the capsule and, therefore,
the risk of offsetting of both parts was very high. In fact, in the conventional solutions,
it usually happens that the leading edge of the enclosing member presses simultaneously
on several annular protrusions, which allows liquid leak channels to be easily formed.
[0015] Thus, with this arrangement, two curves of contact with the walls delimiting the
groove are obtained. In the case where a greater deformation occurs, these two sealing
curves may be small annular surfaces, but in any case, owing to the reduced area thereof,
the pressure exerted by the enclosing member on the walls of the groove increases
and the fluid tightness is notably improved at this point. Should any fluid manage
to cross through the first contact curve, that is, that of the inner diameter of the
enclosing member in contact with the side wall of the capsule, the liquid, under a
much lower pressure, will run up against the remote wall of the groove, which hinders
the fluid losses in the sealing member. Consequently, the beverage may be prepared
under high pressures and the best organoleptic properties thereof may be obtained.
[0016] The invention further includes a number of preferred features that are object of
the dependent claims and the utility of which will be highlighted hereinafter in the
detailed description of an embodiment of the invention.
[0017] Particularly preferably, the leading edge has an annular cross section defining an
inner diameter and an outer diameter and said groove has a floor defining a floor
diameter and said floor diameter is greater than said inner diameter of the enclosing
member and smaller than said outer diameter of the enclosing member. Thus, reliable
contact with both walls of the groove is guaranteed at all times.
[0018] Preferably, the capsule has the shape of a bell-shaped cup, which favours the guidance
of the capsule from the time when the leading edge of the enclosing member makes contact
with the side wall of the capsule.
[0019] In a particularly preferred embodiment, the capsule has the shape of a frustroconical
bell-shaped cup allowing more progressive guidance and subsequent centering.
[0020] Particularly preferably, the capsule has a guide area on said side wall extending
from the floor of said annular groove to at least one third of the height of said
capsule, which starts the mutual guiding of capsule and enclosing member at a very
early stage during the approach method and increases the correct centering of both
parts together.
[0021] In a particularly preferred embodiment, the inner wall of said enclosing member and
the side wall of said capsule have mating shapes in said guide area, which notably
reduces the centering movements at the time prior to closure and minimizes the volume
of liquid existing between the capsule and the enclosing member, such that when opening
the device at the end of preparing the beverage, there are less losses of fluid.
[0022] In another embodiment, said remote wall of said sealing member is formed by a deformable
annular protrusion. Also particularly preferably, said rib is plastically deformable
to improve even more the fluid tightness. Nevertheless, said deformation may also
be elastic.
[0023] Preferably, said remote wall comprises a plurality of punctual blind holes penetrating
in said sealing member in such a way that said sealing member is deformable under
pressure during the preparation of said infusion. Thereby, the sealing member its
facilitates the occurrence of a plastic deformation of this wall of the sealing member
under pressure during the preparation of said infusion, which improves the fluid tightness
a little more.
[0024] In a preferred embodiment, said groove narrows from said injection side towards said
extraction side asymmetrically to optimize on which side of the groove it is desired
to obtain a greater fluid tightness. In an alternative embodiment, the groove could
be symmetrical.
[0025] In another embodiment, the slope angle of said side wall of said main body relative
to said main axis is greater than the slope angle of said remote wall relative to
said main axis. Thanks to this, further to working on the fluid tightness, the centering
angle of the capsule relative to the machine may be optimized and thereby the progressivity
of the centering may be optimized.
[0026] Also, with a view to providing a capsule for preparing infusions indicated at the
beginning which guarantees good fluid tightness in the closing area of the enclosing
member on the capsule and that this fluid tightness may be obtained in a simple, but
reliable way, the invention proposes a capsule of the type indicated at the beginning
characterized in that the sealing member comprises an annular groove surrounding the
main body and which is formed by the side wall of said main body and a remote wall
from said main body, said groove narrowing from the injection side towards the extraction
side and in that, said side wall in the region of said groove slopes between 14 and
17.5° relative to said main axis, said remote wall slopes between 15 and 45º relative
to said main axis, the said groove has a maximum height comprised between 0.8 and
3 mm measured from the lowest point of said extraction side and a depth comprised
between 0.5 and 1.5 mm measured from said maximum height, to the floor of said groove.
[0027] Finally, the invention relates to a method for preparing infusions from a capsule
and a device such as those described above which is characterized the sealing member
comprises an annular groove surrounding the main body and which is formed by the side
wall of said main body and a remote wall from said main body, said groove narrowing
from the injection side towards the extraction side, and in that in said operative
position, said leading edge is inserted in said groove and is sealingly compressed
simultaneously on said side wall of said main body and said remote wall prior to causing
said liquid to pass under pressure through said inner chamber.
[0028] Likewise, the invention also includes other features of detail illustrated in the
detailed description of an embodiment of the invention and in the accompanying figures.
Brief description of the drawings
[0029] Further advantages and features of the invention will become apparent from the following
description, in which, without any limiting character, preferred embodiments of the
invention are disclosed, with reference to the accompanying drawings in which:
Further advantages and features of the invention will become apparent from the following
description, in which, without any limiting character, preferred embodiments of the
invention are disclosed, with reference to the accompanying drawings in which:
Figure 1 is a cross section view along a central plane of a first embodiment of a
capsule according to the invention.
Figure 2 is an enlarged detail of the region of the sealing member of the capsule
of Figure 1, with the unit for preparing infusions according to the invention in the
operative position.
Figure 3 is a partial section view of the unit for preparing infusions according to
the invention, during the passage from the rest position to the operative position.
Figure 4 is a partial section view of the unit for preparing infusions according to
the invention, in the operative position.
Figure 5 is an enlarged detail of the region of the sealing member of the capsule,
with a second embodiment of the unit for preparing infusions according to the invention
in the operative position.
Figure 6 is a section view along a central plane of a second embodiment of a capsule
according to the invention.
Figure 7 is a cross section view along a central plane of a third embodiment of a
capsule according to the invention.
Figure 8 is an enlarged detail of the region of the sealing member of the capsule,
with a third embodiment of the unit for preparing infusions according to the invention
in the operative position.
Detailed description of embodiments of the invention
[0030] Figure 1 shows a first embodiment of a capsule 2 for use in the unit 1 according
to the invention.
[0031] The capsule 2 comprises a cup-shaped, preferably bell-shaped and, more preferably,
a truncated-cone-shaped or cylindrical main body 6. In principal, the cross section
of the capsule will be circular, but it could also have other forms, such as polygonal
or the like.
[0032] The capsule 2, in this case of truncated cone shape, defines a main axis 28. The
truncated cone has an upper base 8 and a lower base 10. In this embodiment, the upper
base 8 ends forming a truncated-cone-shaped cap and is closed. Nevertheless, as will
be seen in other embodiments, this upper base may be flat and have holes or be open
and covered with a sheet. The upper base 8 could also end in the form of a spherical
cap or other forms.
[0033] On the lower base 10 side, the capsule has a perimetrical rim 12 projecting outwardly
from the main body 6. This rim 12 has an injection side 30, corresponding to the side
where the main body 6 is and an extraction side 32. It will be seen in Figure 1 that
the on the extraction side 32, the capsule 2 has a lid 26 made from a sheet-like material,
for closing the lower base 10 and forming an inner chamber 4 with the main body 6,
in which there is contained an infusion product. The perimetrical rim 12 of the capsule
according to the invention may also project outwardly forming an angle relative to
the horizontal in the figures. Nevertheless, the rim 12 usually projects outwardly
radially and on the plane perpendicular to the main axis 28 of the capsule 2.
[0034] In the preferred embodiment, the main body 6 and the lid 26 are made from materials
having barrier properties. In the invention, a material having barrier properties
refers to a material which does not let oxygen pass therethrough or allows it to pass
at very low levels. Particularly preferably, the barrier materials according to the
invention are those having an oxygen transmission rate (OTR) of less than or equal
to 0.1 cm
3/package per day. In the measurement the package of the oxygen transmission rate refers
to a capsule closed with the lid itself. Thanks to this, infusion product is preserved
longer and better in the inner chamber 4. Appropriate materials for providing barrier
properties are, for example, high density polyethylene (HDPE), aluminium, materials
composed of different layers of polymer and metals, cellulose or others. Also preferably,
the main body 6 will be made by injection of a polymer or by forming from a sheet
of aluminium or heat-forming from a sheet of polymeric material.
[0035] In alternative embodiments, to obtain more environmentally sustainable solutions,
the invention also contemplates the possibility of using other materials, such as
polylactic acid or cellulose for the main body 6 and the lid 26.
[0036] Any type of infusion may be produced in the capsule 2 according to the invention,
such as coffee, tea, cocoa, mate or the like or also soluble products.
[0037] On the injection side 30 of the rim 12, the capsule 2 is provided with a sealing
member 14. The sealing member 14 comprises an annular groove 16 surrounding the main
body 6. As may be seen in the figures, the groove 16 is formed by the side wall 18
of the main body 6 and a remote wall 20 from the main body 6. This groove 16 narrows
from the injection side 30 towards the extraction side with an asymmetrical approximately
V shape and extends to a floor 38 of the groove 16. Particularly, the slope angle
of the side wall 18 of the main body 6 relative to the main axis 28 is greater than
the slope angle of said remoter wall 20 relative to the same axis. it should also
be pointed out that the symmetrical V or straight wall shape as the side wall 18 it
is not absolutely necessary. Both walls may be slightly concavely or convexly shaped
and would provide the same effect. In any case, in the invention the walls must narrow
towards the floor 38 of the groove 16 and not be vertical. Thus, in the operative
position, simultaneous contact of the enclosing member 102 against both walls may
be guaranteed, by bearing against tight curves all around it. In the case of a greater
deformation, these curves could be small annular surfaces on each of the side walls
of the groove 16.
[0038] The configuration of the unit 1 for preparing infusions according to the invention
is better to be seen in Figures 3 and 4. Further to the capsule 2, the unit 1 comprises
a device 100 for preparing infusions, shown very schematically in the figures. The
device 100 is a machine for preparing infusions from single-dose capsules, by causing
a liquid, such as, for example, water, to pass under pressure at between 1 and 20
bar through the inner chamber 4 of the capsule 2 and which is common in the conventional
art.
[0039] In the figures there is shown only one enclosing member 102 provided on the injection
side of the device 100 and an extraction wall 106 on the extraction side. This enclosing
member 102 is configured to receive the capsule 2 in the interior thereof. Opposite
to this enclosing member 102, the device 100 there is the fixed extraction wall 106,
provided with liquid passages 108 and perforation means 110, against which the capsule
2 may be opened by the liquid pressure.
[0040] It may also be appreciated in the figures that the enclosing member 102 is provided
with a leading sealing edge 104.
[0041] The unit 10 has a rest position in which the leading sealing edge 104 is remote from
the sealing member 14 and an operative position in which the leading edge 104 of the
enclosing member 102 is compressed against the sealing member 14.
[0042] As explained hereinabove, to obtain optimum results in the preparation of the beverage,
it is important to achieve good fluid tightness the perimetrical contact area between
the leading edge 104 and the sealing member 14. Thus, to solve this problem, during
the preparation of the beverage, the groove 16 and the leading edge 104 are configured
such that, in the operative position, the leading edge 104 is inserted in the groove
16 and is sealedly compressed, simultaneously against the side wall 18 of the main
body 6 and the remote wall 20 of the groove 16. This feature is to be seen particularly
well in Figure 2. Thanks to this, there are formed two perimetrical curves of contact
between the enclosing member 102 and the sealing member 14, notably improving the
fluid tightness. It should also be highlighted that another important advantage in
the unit according to the invention is provided by the fact that the side wall 8 itself
of the capsule 2 forms part of the groove 16, such that a guiding function is obtained
in the leading edge 104 making it very hard for offsetting to occur between the enclosing
member 102 and the capsule 2. As already explained hereinabove, such offsetting was
one of the unresolved problems of the conventional capsules.
[0043] This guidance provided by the walls of the groove 14 itself is notably improved when
the capsule 2 itself also has a guide area 22 on the side wall 18 extending from the
floor of said annular groove 16 to at least one third of the height of said capsule
2. Thereby, the capsule 2 progressively places itself correctly, as shown in Figures
3 and 4.
[0044] Also, in this first embodiment of the capsule 2 according to the invention, the inner
wall of the enclosing member 102 and the side wall 18 of the capsule 2 have mating
shapes in the guide area.
[0045] The grove 16 of the capsule 2 according to the invention may be formed in different
forms. For example, the rim 12 could be simply a completely flat disc such as for
example in Figure 5, and the groove 16 would only be a peripheral indentation of any
optimum profile to fulfil the desired function. Nevertheless, in the embodiment shown
in the figures, the remote wall 20 of the sealing member 14 is formed between the
side wall of the main body 6 and an annular protrusion 24, preferably deformable on
being compressed by the enclosing member 102. The deformation may be elastic, but
it could also be plastic.
[0046] In one particular embodiment providing the technical effect pursued by the invention,
the leading edge 104 of the enclosing member 102 has an inner diameter 112 comprised
between 29.8 and 30.4 mm and an outer diameter 114 comprised between 30.6 and 32 mm.
In turn, in the capsule 2, the side wall 18 in the region of the groove 16 is inclined
between 14 and 17.5° relative to the main axis 28, while thee the remote wall 20 is
inclined between 15 and 45º relative to the same main axis 28. On the other hand,
the groove 16 has a maximum height 34 comprised between 0.8 and 3 mm measured from
the lowest point of the extraction side, and a depth 36 comprised between 0.5 and
1.5 mm measured from the maximum height 34 to the floor 38 of the groove 16. As may
be seen in Figure 2, the floor 38 of the grove 16 is the lowest point thereof. Thus,
for example, one way of measuring the depth 36 if the floor 38 ends in a radius, would
be to measure the distance between the maximum height 34 and the point of tangency
of the radius marking the floor 38.
[0047] The method for preparing infusions according to the invention, from a capsule 2 and
a device 100 such as those described in the foregoing paragraphs, is as follows: firstly,
the capsule 2 is inserted in the device 100 and more particularly in the capsule holder
which is formed by a fixed part and a moving part. In the example shown in Figures
3 and 4, the fixed part is the extraction wall 106 while the moving part is the enclosing
member 102. Nevertheless, both parts could have exchanged functions, such that the
extraction wall 106 would move and the enclosing member 102 would be static. On the
other hand, the device 100 may have a vertical or horizontal capsule holder. That
is, when the capsule 2 is put into place, the rim 12 may be in a horizontal or vertical
position. Especially if the capsule 2 is placed in a horizontal position, then the
extraction wall 106 would include a guide for holding the capsule rim.
[0048] The unit 1 according to the invention has a rest position in which the capsule 2
is inserted in the device 100. In this starting position, not shown in the figures,
the enclosing member 102 and, more particularly, the leading edge 104 is remote or
separated from the sealing member 14 of the capsule 2. From this position, the movement
of the enclosing member 102 towards the extraction wall 106 starts. Figure 3 shows
an indeterminate moment of this movement. At this moment, the main axis 28 of the
capsule 2 is not parallel relative to the axis 116 of the enclosing member 102. Nevertheless,
as from when the enclosing member touches the guide area 22, it starts correcting
the orientation of the capsule 2 in order progressively to cause the main axis 22
and the axis 116 of the enclosing member 102 to align so that the capsule 2 is centered
relative to the enclosing member 102. The offsetting between the capsule 2 and the
enclosing member 102 may be caused by a linear movement between the main axis 28 and
the axis 116 of the machine, namely, both axes would be parallel, but not coaxial.
An angular movement between both axes could occur, or finally, a combination of angular
and linear movements.
[0049] Precisely, this guiding allows the leading edge 104 of the enclosing member 102,
as it approaches the extraction wall 106, to be inserted without difficulty in the
groove 16 of the capsule 2 and the unit 1 assumes an operative position in which the
leading sealing edge 104 is compressed against the sealing member 14. This provides
the fluid tightness, as shown in Figure 4, and the alignment between the enclosing
member 102 and the capsule 2 is optimum. It should also be pointed out that the guiding
prevents the enclosing member 102 from pressing outside the groove 16, which would
cause liquid losses during the preparation of the beverage. In any case, to achieve
the optimum fluid tightness, the most important requirement is that the floor diameter
40 of the groove 16 should be greater than the inner diameter 112 of the enclosing
member 102 and, in turn, smaller than the outer diameter 114 of the enclosing member
102 and that it should progressively narrow towards the floor 38, which is to be seen
clearly in Figure 2. Particularly, in this case, the floor diameter is defined either
as the distance between the main axis 28 of the capsule 2 and the point of intersection
of the side and remote walls 18, 20, or, if this intersection point is rounded, as
the distance between the main axis 28 and the centre of the radius between these two
curves. The skilled person will know different ways of measuring this geometry, such
as, for example, by a profile projector, or with a similar measuring system.
[0050] The enclosing member 102 also has punches 118 at the bottom thereof. These are configured
so that, when passing to the operative position, they perforate the upper base 8 of
the capsule 2, as shown in Figure 4.
[0051] In this situation, the method of infusion can be started. To this end, the pump 120
which injects the fluid under a pressure of between 1 and 20 bar in the inner chamber
4 is activated. Due to this, there is produced an increase in pressure causing the
lid to swell and be compressed against the perforation means 110 (see Figure 2) and
therefore open passages in the extraction side of the capsule 2 and the infusion flows
to the outside through the passages 108 provided in the extraction wall 106. From
here on, the infusion is directed to a not shown manifold and is channelled towards
the container receiving the infusion.
[0052] Hereinafter there are illustrated other embodiments of the unit 1 according to the
invention sharing a large portion of the features described in the foregoing paragraphs.
Consequently, hereinafter there will be described only the differentiating members,
while for the common members reference is made to the description of the first embodiment.
[0053] In Figure 5, there is to be seen an embodiment in which the inner wall of the enclosing
member 102 is not parallel to the guide area 22. In this case, the guiding is effected
only by the leading edge 104 of the enclosing member 102.
[0054] In the embodiment of Figure 6, the upper base 8 of the main body 6 has a plurality
of first passages 42, while the lid 26 has also a plurality of second passages 44.
In this case, the capsule 2 itself would not have a barrier property. To this end,
to guarantee a good preservation of the infusion product, the capsule 2 must be packaged
in a laminate having this property such as, for example, a laminate composed of aluminium
and a polymer such as polythene.
[0055] The embodiment of Figure 7 is differentiated by the fact that the upper base 8 is
open. Thus, in this case, the opening is covered with an upper laminated covering
46 made from materials such as aluminium or a polymer or combinations thereof. The
upper covering 46 may have characteristics similar to those of the lid 26.
[0056] In the embodiment of Figure 8, the remote wall 20 of the sealing member 14 comprises
a plurality of punctual blind holes 48 penetrating in this wall of the sealing member
14. This embodiment is especially advantageous, since the support surface for the
leading edge 104 of the enclosing member 102 is reduced and a greater surface pressure
is obtained. This facilitates the occurrence of a plastic deformation of this wall
and that, therefore, a better fluid tightness is achieved between the enclosing member
102 and this wall of the sealing member 14.
[0057] The embodiments described up to here represent non-limiting examples, such that the
man of the art will understand that, beyond the examples shown, within the scope of
the invention, multiple combinations among the features claimed and the embodiments
shown are possible.
1. A unit for preparing infusions comprising:
[a] a capsule (2) comprising:
[i] a cup-shaped main body (6) defining a main axis (28) and having an upper base
(8) and an open lower base (10),
[ii] a lid (26) for closing said lower base (10) and forming an inner chamber (4)
with said main body (6) in which there is contained an infusion product,
[iii] a perimetrical rim (12) projecting outwardly from said lower base (10) and having
an injection side (30) and an extraction side (32), and
[iv] a sealing member (14), provided on said injection side of said rim (12), and
[b] a device (100) for preparing infusions comprising an enclosing member (102) configured
to receive said capsule (2) and having a leading sealing edge (104), said device (100)
being configured to prepare an infusion by causing a liquid to pass under pressure
through said inner chamber (4),
[c] said unit having a rest position in which said leading edge (104) is remote from
said sealing member (14) and an operative position in which said leading sealing edge
(104) is compressed against said sealing member (14) to provide fluid tightness during
the preparation of said infusion,
characterized in that
[d] said sealing member (14) comprises an annular groove (16) surrounding the main
body (6) and which is formed by the side wall (18) of said main body (6) and a remote
wall (20) from said main body (6), said groove (16) narrowing from the injection side
(30) towards the extraction side (32), and in that
[e] said groove (16) and said leading edge (104) are configured in such a way that,
in the operative position, said leading edge (104) is inserted in said groove (16)
and is sealingly compressed simultaneously on said side wall (18) of said main body
(6) and said remote wall (20).
2. The unit of claim 1,
characterized in that said leading edge (104) has an annular cross section defining an inner diameter (112)
and an outer diameter (114) and said groove (16) has a floor (38) defining a floor
diameter (38) and
in that said floor diameter (40) is
[a] greater than said inner diameter (112) of the enclosing member (102) and
[b] smaller than said outer diameter (114) of the enclosing member (102).
3. The unit according to any of claims 1 or 2, characterized in that said capsule (2) has a guide area (22) on said side wall (18) extending from the
floor (38) of said annular groove (16) to at least one third of the height of said
capsule (2).
4. The unit of claim 3, characterized in that the inner wall of said enclosing member (102) and the side wall (18) of said capsule
(2) have mating shapes in said guide area (22).
5. The unit according to any of claims 1 to 4, characterized in that said remote wall (20) of said sealing member (14) is formed by a deformable annular
protrusion (24).
6. The unit according to any of claims 1 to 5, characterized in that said remote wall (20) comprises a plurality of punctual blind holes (48) penetrating
in said sealing member (14) in such a way that said sealing member (14) is deformable
under pressure during the preparation of said infusion.
7. The unit according to any of claims 1 to 6, characterized in that said groove (16) narrows from said injection side (30) towards said extraction side
(32) asymmetrically.
8. The unit of claim 7, characterized in that the slope angle of said side wall (18) of said main body (6) relative to said main
axis (28) is greater than the slope angle of said remote wall (20) relative to said
main axis (28).
9. A capsule for use in a device (100) for preparing infusions comprising a truncated-cone-shaped
enclosing member (102) configured to receive said capsule (2) and having a circular
leading sealing edge (104), said device (100) being configured to prepare an infusion
by causing a liquid to pass under pressure through said inner chamber (4) and said
leading edge (104) having an inner diameter (112) comprised between 29.8 and 30.4
mm and an outer diameter comprised between 30.6 and 32 mm, said capsule (2) comprising
[a] a truncated cone cup-shaped main body (6) defining a main axis (28) and having
an upper base (8) and an open lower base (10),
[b] a lid (26) for closing said lower base (10) and forming an inner chamber (4) with
said main body (6) in which there is contained an infusion product,
[c] a perimetrical rim (12) extending outwardly from said lower base (10) and having
an injection side and an extraction side, and
[d] a sealing member (14), provided on said injection side of said rim (12).
characterized in that said sealing member (14) comprises an annular groove (16) surrounding the main body
(6) and which is formed by the side wall (18) of said main body (6) and a remote wall
(20) from said main body (6), said groove (16) narrowing from the injection side (30)
towards the extraction side (32) and
in that,
[e] said side wall (18) in the region of said groove slopes between 14 and 17.5º relative
to said main axis,
[f] said remote wall (20) slopes between 15 and 45º relative to said main axis,
[g] said groove has a maximum height (34) comprised between 0.8 and 3 mm measured
from the lowest point of said extraction side (30) and a depth (36) comprised between
0.5 and 1.5 mm measured from said maximum height, to the floor (38) of said groove
(16).
10. A method for preparing infusions comprising the steps of:
[a] inserting a capsule (2) comprising:
[i] a cup-shaped main body (6) defining a main axis and having an upper base (8) and
an open lower base (10),
[ii] a lid (26) for closing said lower base (10) and forming an inner chamber (4)
with said main body (6) in which there is contained an infusion product,
[iii] a perimetrical rim (12) projecting outwardly from said lower base (10) and having
an injection side and an extraction side, and
[iv] a sealing member (14), provided on said injection side (30) of said rim (12),
[b] in a device (100) for preparing infusions comprising an enclosing member (102)
configured to receive said capsule (2) and having a leading sealing edge (104), said
device (100) being configured to prepare an infusion by causing a liquid to pass under
pressure through said inner chamber (4),
[c] said unit having a rest position in which said leading edge (104) is remote from
said sealing member (104) and an operative position in which said leading sealing
edge (104) is compressed against said sealing member (14) to provide fluid tightness
during the preparation of said infusion,
characterized in that
[d] said sealing member (14) comprises an annular groove (16) surrounding the main
body (6) and which is formed by the side wall (18) of said main body (6) and a remote
wall (20) from said main body (6), said groove (18) narrowing from the injection side
(30) towards the extraction side, and in that
[e] in said operative position, said leading edge (104) is inserted in said groove
(16) and is sealingly compressed simultaneously on said side wall (18) of said main
body (6) and said remote wall (20) prior to causing said liquid to pass under pressure
through said inner chamber (4).